Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash Flows From Operating Activities:
Net income	$ 3,860	$ 14,840
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Impairments included in discontinued operations	0	1,988
Stock-based compensation expense	1,677	436
Depreciation and amortization	9,856	5,127
Adjustment of deferred income taxes	(2,159)	(14,804)
Other	230	836
Changes in operating assets and liabilities, net of effects of acquisitions:
Accounts receivable	2,144	(12,861)
Prepaid expenses and other assets	(2,025)	(764)
Accounts payable	(1,990)	933
Accrued expenses and other liabilities	1,914	(1,107)
Net cash used in operating activities of discontinued operations	0	(257)
Net cash provided by (used in) operating activities	13,507	(5,633)
Cash Flows From Investing Activities:
Purchases of businesses, net of cash acquired	(1,100)	(52,492)
Purchases of property and equipment	(3,951)	(4,078)
Investment in associated company	(4,000)	0
Purchases of marketable securities	(123,015)	(392,898)
Sales of marketable securities	45,065	490,932
Maturities of marketable securities	122,115	27,500
Net cash provided by investing activities of discontinued operations	0	80
Net cash provided by investing activities	35,114	69,044
Cash Flows From Financing Activities:
Repurchases of common stock	(8,848)	0
Repayments of capital lease obligations	(213)	(32)
Repayments of long-term debt	(13,000)	(1,000)
Net cash used in financing activities	(22,061)	(1,032)
Net increase in cash and cash equivalents	26,560	62,379
Effect of foreign currency translation on cash and cash equivalents	26	3
Cash and cash equivalents, beginning balance	71,556	8,487
Cash and cash equivalents, ending balance	$ 98,142	$ 70,869